As laws restricting cannabis are eased around the United States, we’re exploring the implications for road safety.

A lot is known about how alcohol impairs a person’s ability to drive safely. For decades, the police have had tools to detect whether drivers have more alcohol in their system than is legally permissible.

But when it comes to marijuana, government officials and the private sector are struggling to come up with effective policies. Some states have a zero tolerance approach. Others have set legal limits similar to those used for alcohol impairment, but there is no national consensus on what those limits should be.

Then there’s the challenge of detection. Blood tests can show whether someone has used cannabis recently, but experts say they don’t reliably measure impairment. Some states, like Minnesota, are testing whether saliva tests do a better job.

We’re trying to get a sense of how people are thinking about marijuana use and safety on the roads.

We will not publish any part of your response without contacting you first, and we will never publicly share your personal information.